Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality Planning Purposes; Redesignation of the Philadelphia County Carbon Monoxide Area to Attainment and Approval of the Area's Maintenance Plan and the Philadelphia County 1990 Base Year Carbon Monoxide Emission Inventory; Commonwealth of Pennsylvania

EPA is approving a maintenance plan and a request to redesignate part of Philadelphia County from nonattainment to attainment for carbon monoxide (CO) and is also approving the 1990 base year CO emissions inventory for Philadelphia County. The maintenance plan, redesignation request and 1990 base year CO emissions inventory were submitted by the Commonwealth of Pennsylvania. Under the 1990 amendments of the Clean Air Act (CAA) designations can be revised if sufficient data is available to warrant such revisions. In this action, EPA is approving the Pennsylvania request because it meets the maintenance plan and redesignation requirements set forth in the CAA. This action is being taken under section 110 of the CAA.